1. Field of the Invention
This invention relates to a fluorescent foil, especially for use within the sign and advertising trade.
In one field of application for such fluorescent foils within the sign and advertising trade, the foil is cut to letters and/or figures, emblems, logograms and the like which are adhered onto e.g. a window pane or a corresponding disc or plate of glass, plexiglass or similar transparent/translucent materials which thereby constitutes a carrier for the sign/advertisement. In order to give the sign/advertisement the desired glowing neon-like effect, the same must be illuminated by means of so called invisible or black light.
2. Description of the Related Art
There exists adhesive fluorescent foils of this kind. These known sign/advertisement-foils are white and non-translucent. At one side face thereof, a layer of fluorescent matter has been applied to these foils, the opposite side face carrying an adhesive layer having an external protective paper layer to be torn off and which serves to protect the adhesive layer prior to the time of use.
When adhered onto e.g. a glass or plexiglass pane, these known foils in the form of letters and/or figures will exhibit a front face (the external surface of the fluorescent layer) and a rear side (the interface between the adhesive layer and the adjacent pane face), the intermediate, carrying, white and non-translucent foil layer preventing illumination through the layers when said front face is illuminated by black light. The sign and/or advertising letters etc. have the very same shape as seen from said rear side, but an attractive "advertising effect" cannot be obtained there, this representing an obvious disadvantage in the fields of application concerned.
Likewise, it represents a serious disadvantage and a limitation of use that the illuminating source for black light must be positioned at that side to which the fluorescent layer is facing. With such an external or outdoor positioning of the light source, the latter is subjected to theft and wilful damage, and the placement of such signs and/or advertisement on cars is practically out of the question. With outdoor sign/advertisement, the absolutely necessary external positioning of the fluorescent layer will cause its deterioration, wearing and damage through external influences, such as the sun, weather and wind.
These deficiencies, disadvantages and application limitations in adhesive fluorescent sign/advertisement-foils are in so far remedied to a certain degree by means of a foil of the kind concerned made of a translucent foil material admixed colouring matter and fluorescent matter. Such a foil is disclosed in Norwegian patent application No. 902755 (not published).
Nevertheless, the adhesive fluorescent foil according to Norwegian patent application No. 902755 has application limitations and, thus, cannot be used to create special decorative effects such as when adhering two corresponding mirror-symmetrical overlapping foil letters/figures, one at each side of a glass or plexiglass pane--the two mirror-symmetrical letters/figures being given a different colour, and wherein one may alternate between the colours singly and in combination through alternating illumination from two illumination sources for black light, one at each side of said pane.
The fluorescent foil according to Norwegian patent application No. 902755 is not protected against UV-radiation; this shortens its useful life substantially.